1. Field of the Invention
This invention relates to method and apparatus for securing a protective bed liner to a cargo bed of a truck and more particularly to a one-piece molded fastener for securing the walls of the bed liner to a downwardly extending flange of a rail on a cargo bed side wall.
2. Description of the Prior Art
Fasteners for securing panels of sheet material to a supporting structure are well known in the art and particularly for connecting parts to the frame of an automotive vehicle. U.S. Pat. Nos. 2,853,913; 3,029,486; 3,093,027; 4,122,583; and 4,470,737 are representative of panel clips and fasteners that are used to connect automotive trim to the vehicle body and the fire wall to the vehicle body. The clips and fasteners disclosed in the above patents include an expandable portion that is forced through a restricted opening in the panel and the supporting wall to secure the panel to the supporting wall. Typically, the clips are one-piece, molded plastic bodies.
U.S. Pat. Nos. 3,093,874; 4,708,895; and 4,765,036 disclose one-piece automotive trim fasteners that include a resilient locking portion that is compressible to permit the fasteners to be engaged so that when the fastener is installed the locking portion is released to frictionally engage the wall of the supporting structure.
With the plastic clips and fasteners disclosed in the above-identified patents, it is necessary to pass the clip through aligned holes in the sheet member or panel and the wall of the supporting structure. If the wall of the supporting structure does not include a hole, then one must be drilled, for example, into the vehicle body to receive the clip. This is particularly undesirable when a hole must be drilled in the metal body of the vehicle. If clips and fasteners of this type are used to secure a protective bed liner to a truck cargo bed, holes must be drilled in the side walls or flange portions of the truck bed. This can lead to rusting and deterioration of the side wall around the holes.
To avoid drilling holes in metal supporting walls for receiving clips and fasteners to secure sheet member panels in place, non-invasive fasteners have been proposed. One type of non-invasive fastener utilizes a toggle bolt as disclosed in U.S. Pat. Nos. 1,135,612 and 1,648,927. Toggle bolt-clamps, however, are limited in use because they have dimensional and structural features that restrict their usage.
One of the problems encountered in securing a protective liner to the cargo bed of a pickup truck is providing a fastener that can connect a bed liner to a number of different designs of truck bed side walls and flanges. The flanges themselves vary considerably in dimension and configuration. For example, a truck bed rail flange may be vertical or angular and of varying length with or without an extending lip. Therefore, a bed liner fastener must be adaptable to a wide range of cargo bed designs to avoid customizing fasteners for each cargo bed design. Without the provision of a versatile fastener, the availability of fasteners for the different designs of cargo beds becomes unmanageable.
To meet the growing demand for installing protective liners on all types of truck cargo beds, a number of fasteners have been proposed that are adaptable to a wide range of cargo bed styles. These types of fasteners are also preferred because they do not require that holes be drilled in the truck bed side walls.
U.S. Pat. Nos. 4,181,349; 4,572,568; 4,595,229; 4,659,133; 4,740,026; 4,768,822; 4,796,942; and 4,850,633 are examples of non-invasive fasteners for truck bed liners that can be used with a number of different styles of truck cargo beds. However, these fasteners require multiple parts, such as wing nuts, bolts and screws, that secure the fastener to the liner and clamp the liner to the bed side wall flange. Substantial inventory and order problems are encountered with any type of fastener that includes multiple pieces. The pieces must be properly packaged to see that all components are provided, and the installer must exercise care to see that all the pieces are available for installation.
To overcome the problems encountered with multi-piece non-invasive fasteners for truck bed liners, one-piece fasteners have been proposed. An example one-piece fastener, not necessarily for bed liners, fabricated of resilient material is disclosed in U.S. Pat. No. 4,677,714. U.S. Pat. No. 4,924,561 discloses a one-piece fastener that includes a lever for securing the fastener in a hole of a panel for mounting electric wire to the panel.
One-piece fasteners for bed liners are disclosed in U.S. Pat. Nos. 4,906,040; 5,046,775; and 5,150,940. With the fastener disclosed in U.S. Pat. No. 4,906,040 a pair of vertically spaced slots must be cut in the bed liner with a ridge formed in the liner wall between the slots to receive and retain a resilient clip. The clip has end portions which extend through the slots and a central body portion that frictionally engages the ridge. An upper end of the clip extends through one slot into underlying wedging engagement with the flange of the truck side wall. A lower end of the clip engages the opposite surface of the liner wall. While this device secures the liner to the truck bed wall with a single resilient piece, the liner wall must be specially constructed to receive and retain the resilient clip in place.
U.S. Pat. Nos. 5,046,775 and 5,150,940 utilize one-piece resilient clips or fasteners which do not require that the bed liner be specially constructed to receive the fastener, other than forming an opening or aperture in the liner wall. Each of these fasteners includes a unitary molded piece requiring no tools for installation and features a snap-engagement with the flange of the truck bed rail to hold the liner securely in place. No holes are required to be drilled in the truck bed side nor screws or other multi-piece fasteners used.
The known one-piece bed liner fasteners include an arcuately shaped clamping member rigidly connected to a base plate. The clamp member is extended through the hole in the bed liner and is snapped into locking engagement with the rail flange. The clamping member is urged against the rail flange, and the base plate is compressed against the liner side wall to secure the bed liner to the cargo bed. With this arrangement, the liner side wall is securely and tightly held against the rail flange by opposing forces exerted by the clamp member and base plate.
With the one-piece fasteners, as disclosed in U.S. Pat. Nos. 5,046,775 and 5,150,940, the arcuately shaped clamp member is rigidly connected to the base plate. This requires bending the base plate relative to the clamp member to permit the fastener to snap in place and compress the liner on the rail flange. This has the effect of placing significant bending stresses on the point of connection of the base plate to the clamp member. Consequently, the base plate is subject to cracking or breaking, rendering the fastener inoperative.
U.S. Pat. No. 4,305,182 discloses a C-shaped spring retainer clip for a refrigerator door gasket that overcomes the adverse effects of bending rigid C-shaped fasteners. A C-shaped bed liner fastener that does not require pivoting or bending of the base plate relative to the clamp member is manufactured and sold by Futurex Automotive Division of Futurex Industries, Inc., Marshall, Indiana. While this fastener does not rely upon the snap-in action of the one-piece fasteners described above, it requires that the base plate be held in position on the liner by a screw to maintain the end of the C-shaped clamp member compressed against the flange of the truck bed rail.
While it has been suggested by the prior art devices to provide a resilient one-piece fastener for tightly securing the wall of a bed liner to the flanged rail of a truck cargo bed, the prior art devices require bending or flexing of the rigidly connected parts. This places stress on the fastener tending to break the fastener. In the alternative, those fasteners which require multi-piece components to clamp the bed liner to the truck bed rail are not convenient to install.
Therefore, there is need for a resilient one-piece bed liner fastener that is non-invasive and requires no tools for installation. The fastener must be easily snapped in place without requiring excessive flexing or bending of the clamp member relative to the base plate.